class Solution {
public:
    int findPeakElement(vector<int>& nums) {
        int left=0,right=nums.size()-1;
        while(left<right)
        {
            int mid=left+(right-left+1)/2;
            if(nums[mid]>nums[mid-1])left=mid;
            else right=mid-1;
        }
        return left;
    }
};
